Over seventy percent of spinal cord injuries are contusions. Contusions cause damaged or lost nervous tissue, demyelinated axons, chronic inflammation, and loss of function. Spinal cord injuries can have a severe effect on the quality of life often effecting the bowel and bladder, cardiovascular, metabolic, pulmonary, and sexual function. Spinal cord contusions can either be complete, meaning no function left below the injury, or incomplete, some function left. The inability of neurons to regenerate and the collapsing of the contused region cause major obstacles for repair. There are three main mechanisms to attacking spinal cord injuries: rescue, regenerate, and rehabilitate.
The study Activity-dependent Spinal Cord Neuromodulation Rapidly Restores Trunk and Leg Motor Functions After Complete Paralysis (Rowald et al, 2022) explores the rehabilitation repair strategy. Epidural Electrical Stimulation (EES) allowed three previously paralyze men to rapidly restore their motor function. All three patients had a complete contusion due to motorcycle accidents (Cueto, 2022). Within a day, the three individuals were able to stand, walk, cycle, swim, and have full control over their trunk movements again (Rowald et al, 2022). All three men were able to take three hundred or more step with the help of body support. Although, critics question what the researchers define as walking and pointed out that patients have over sixty percent of their body weight being supported when they are walking (New York Post, 2022). The researchers targeted the dorsal roots by placing a paddle-shaped device directly on the spinal cord. The electrodes on the paddle directly aligned with the nerve roots. A Medtronic device, which is normally used for Deep Brain Stimulation, was inserted into the three patient’s abdomen. Patients were then capable of controlling their motor neurons, level of stimulation, and what type of activity they wanted to do all with a tablet(Cueto, 2022). While the feat of artificially reactivating motor function to those who are paralyzed is extremely promising, the researchers acknowledged the limitations to their study. They recognized that the paddle used can only be implanted through an invasive needle and requires the spinal cord to be cut down which limits the number of physicians willing to perform the operation. Researchers also acknowledge that in addition to body weight support, “their gate was still clumsy and nonfluid”(Cueto, 2022). Although EES is not a direct cure for paralysis, it is a miraculous feat that can help to restore patients motor function after a spinal cord contusion.
While Rowald’s study focused on the rehabilitation repair mechanism, Dr. Oudega and his colleagues focused on the regeneration of neurons and inflammatory response. In The Effect of A Nanofiber-Hydrogel Composite on Neural Tissue Repair and Regeneration in the Contused Spinal Cord (Li et al, 2020), Dr. Oudega and his colleagues developed a composite (NHC) that could be injected into the contused region of mice and would maintain both the mechanical strength and permeability of the spinal cord. With their composite, they found that there were more M2 macrophages in the contused area. M1 macrophages help with debris clearance, apoptotic cell removal, and sterilization while the M2 macrophage phenotype supports neuron survival, axon growth, and promotes axon re-myelination. In addition to seeing a shift in the macrophage phenotype, they also saw the blood vessel density increase with time all while the spinal cord maintained its diameter, all signs of increasing neuronal regeneration.
Although both research teams are exploring different mechanisms, they have the same general goal in mind of helping repair spinal cord injuries. Potentially combining Dr. Oudega’s regeneration composite and Dr. Rowald’s rehabilitation techniques could be a promising cure to paralysis due to spinal cord injury.
References
Cueto, I., (2022, February 7). Walking again after paralysis: Early study suggests stimulation could jolt spinal cord back to life. STAT. Retrieved March 4, 2022, from https://www.statnews.com/2022/02/07/walking-again-after-paralysis-early-study-suggests-stimulation-could-jolt-spinal-cord-back-to-life/
Li, X., Zhang, C., Haggerty, A. E., Yan, J., Lan, M., Seu, M., Yang, M., Marlow, M. M., Maldonado-Lasunción, I., Cho, B., Zhou, Z., Chen, L., Martin, R., Nitobe, Y., Yamane, K., You, H., Reddy, S., Quan, D.-P., Oudega, M., & Mao, H.-Q. (2020). The effect of a nanofiber-hydrogel composite on Neural Tissue Repair and regeneration in the contused spinal cord. Biomaterials, 245, 119978. https://doi.org/10.1016/j.biomaterials.2020.119978
New York Post. (2022, February 14). Paralyzed men begin walking again after spinal cord implant: Study. New York Post. Retrieved March 4, 2022, from https://nypost.com/2022/02/14/paralyzed-men-begin-walking-again-after-spinal-cord-implant-study/
Rowald, A., Komi, S., Demesmaeker, R., Baaklini, E., Hernandez-Charpak, S. D., Paoles, E., Montanaro, H., Cassara, A., Becce, F., Lloyd, B., Newton, T., Ravier, J., Kinany, N., D’Ercole, M., Paley, A., Hankov, N., Varescon, C., McCracken, L., Vat, M., … Courtine, G. (2022, February 7). Activity-dependent spinal cord neuromodulation rapidly restores trunk and leg motor functions after complete paralysis. Nature News. Retrieved March 4, 2022, from https://www.nature.com/articles/s41591-021-01663-5?%3Futm_medium=affiliate&utm_source=commission_junction&utm_campaign=CONR_PF018_ECOM_GL_PHSS_ALWYS_PRODUCT&utm_content=productdatafeed&utm_term=PID100093539&CJEVENT=765892e99a4611ec802200b50a82b838
No comments:
Post a Comment